Comprehensive Income (AOCI components) (Details) - USD ($) $ in Millions	6 Months Ended
	Jan. 23, 2016	Jan. 24, 2015
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
AOCI Balance	$ 61
AOCI Balance	(807)
Net Unrealized Gains on Available-for-Sale Investments
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
AOCI Balance	310	$ 424
Other comprehensive income (loss) before reclassifications attributable to Cisco Systems, Inc.	(515)	(23)
(Gains) losses reclassified out of AOCI	20	(76)
Tax benefit (expense)	198	49
AOCI Balance	13	374
Net Unrealized Losses Cash Flow Hedging Instruments
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
AOCI Balance	(16)	(12)
Other comprehensive income (loss) before reclassifications attributable to Cisco Systems, Inc.	(24)	(131)
(Gains) losses reclassified out of AOCI	8	30
Tax benefit (expense)	2	3
AOCI Balance	(30)	(110)
Cumulative Translation Adjustment and Actuarial Gains and Losses
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
AOCI Balance	(233)	265
Other comprehensive income (loss) before reclassifications attributable to Cisco Systems, Inc.	(524)	(379)
(Gains) losses reclassified out of AOCI	1	0
Tax benefit (expense)	(34)	36
AOCI Balance	(790)	(78)
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
AOCI Balance	61	677
Other comprehensive income (loss) before reclassifications attributable to Cisco Systems, Inc.	(1,063)	(533)
(Gains) losses reclassified out of AOCI	29	(46)
Tax benefit (expense)	166	88
AOCI Balance	$ (807)	$ 186